Water-resistive barriers include building wraps, felts, self-adhered sheets, fluid-applied coatings and integrated sheathing. They form the drainage plane: water that passes the siding, brick or panel runs down the WRB and out at flashings. Many also act as the air barrier. Laps, penetrations and integration with window flashing decide whether a WRB works.
Fluid-applied WRB goes on the sheathing this week, detail every rough opening before the windows show up.
Window and door openings must be wrapped and pan-flashed in shingle sequence before units go in; fixing it afterward means pulling the windows.
Also heard as
- water-resistive barrier
- building wrap
Related terms
Shingle lap
Overlapping layers so each upper piece lies over the one below, sending water down and out like roof shingles.
Rainscreen
A wall design with cladding held off the WRB by a vented, drained gap so water can escape and the wall can dry.
Sill pan
A tray of flashing under a window or door with a raised back and ends, catching any water that gets past the unit.
Strip-in
To seal the flange of a flashing or fixture to the surrounding membrane with an overlapping strip of tape or sheet.